Searched for: author%3A%22Uijttewaal%2C+W.S.J.%22
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Van Prooijen, B.C. (author), Uijttewaal, W.S.J. (author)
The development of large coherent structures in a shallow mixing layer is analyzed. The results are validated with experimental data obtained from particle tracking velocimetry. The mean flow field is modeled using the self-similarity of the velocity profiles. The characteristic features of the down-stream development of a shallow mixing layer...
journal article 2002
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Cargnelutti, M. (author), Breugem, W.A. (author), Portela, L.M. (author), Mudde, R.F. (author), Uijttewaal, W.S.J. (author), Stelling, G.S. (author)
In this work, a comparison between the results of point-particle direct numerical simulations and PIV/PTV experiments of a particle-laden horizontal channel flow is presented. The numerical simulations were preformed trying to mimic as much as possible the experimental conditions. The accuracy of the point-particle approach was evaluated by...
conference paper 2006
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Cargnelutti, M. (author), Breugem, W.A. (author), Portela, L.M. (author), Mudde, R.F. (author), Uijttewaal, W.S.J. (author), Stelling, G.S. (author)
In this work, a comparison between the results of point-particle direct numerical simulations and PIV/PTV experiments of a particle-laden horizontal channel flow is presented. The numerical simulations were preformed trying to mimic as much as possible the experimental conditions. The accuracy of the point-particle approach was evaluated by...
conference paper 2006
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Van Prooijen, B.C. (author), Uijttewaal, W.S.J. (author)
This study demonstrates the importance of a sophisticated sub-grid model when performing a depth-averaged unsteady RANS simulation of a shallow flow. The reduction of resolution and the spatial dimensions exclude important physical processes as present in three-dimensional turbulence. Especially the effect of the bottom turbulence on the...
journal article 2008
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Van Balen, W. (author), Uijttewaal, W.S.J. (author), Blanckaert, K. (author)
After validation with experimental data, large-eddy simulation (LES) is used to study in detail the open-channel flow through a curved flume. Based on the LES results, the present paper addresses four issues. Firstly, features of the complex bicellular pattern of the secondary flow, occurring in curved open-channel flows, and its origin are...
journal article 2009
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Ali, S. (author), Uijttewaal, W.S.J. (author)
The Objective of this study is to estimate the form drag due to vegetated weir- like obstacles. Head loss due to submerged vegetated dikes and groins has been modeled by expansion loss form drag model (Energy and momentum balance principles) and it has been compared with experimental data. An experimental study has been carried out on a scaled...
conference paper 2009
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Uijttewaal, W.S.J. (author)
public lecture 2009
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Van Balen, W. (author), Uijttewaal, W.S.J. (author), Blanckaert, K. (author)
Large-eddy simulation (LES) is performed of a curved open-channel flow over topography based on the laboratory experiment by Blanckaert [“Topographic steering, flow circulation, velocity redistribution and bed topography in sharp meander bends,” Water Resour. Res., doi:10.1029/2009WR008303 (in press)] . In the experiment, the large-scale bed...
journal article 2010
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Sukhodolov, A.N. (author), Schnauder, I. (author), Uijttewaal, W.S.J. (author)
Shallow lateral shear layers forming between flows with different velocities, though essential for mixing processes in natural streams, have been examined only in laboratory settings using smooth, fixed?bed channels. This paper reports the results of an experimental study of a shear layer in a straight reach of a natural river where the layer,...
journal article 2010
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Crosato, A. (author), Getaneh, A.A. (author), Desta, F.B. (author), Uijttewaal, W.S.J. (author), Le, U. (author)
The current view is that migrating bars are the result of morphodynamic instability in straight or mildly-sinuous alluvial channels and are therefore an inevitable feature of alluvial river beds. Steady bars, instead, require some external forcing or specific morphodynamic conditions to develop. Yet, recent numerical tests showed that steady...
conference paper 2010
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Vermaas, D.A. (author), Uijttewaal, W.S.J. (author), Hoitink, A.J.F. (author)
Research on lateral exchange of streamwise momentum between parallel flows in open channels has mainly been focused on compound channels composed of a main channel and a floodplain, on mixing layer development downstream of river confluences, and on partially vegetated channels. This study aims to establish the mechanisms responsible for...
journal article 2011
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Crosato, A. (author), Mosselman, E. (author), Desta, F.B. (author), Uijttewaal, W.S.J. (author)
Alternate bars in straight alluvial channels are migrating or nonmigrating. The currently accepted view is that they are nonmigrating if the width-to-depth ratio is at the value of resonance or if the bars are forced by a persistent local perturbation. We carried out 2-D numerical computations and a long-duration mobile-bed flume experiment to...
journal article 2011
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Crosato, A. (author), Rajbhandari, N. (author), Comiti, F. (author), Uijttewaal, W.S.J. (author)
Wood transport in rivers, typically occurring during flood events, represents a relevant hazard for its potential to create obstruction at bridges and narrow cross-sections. Therefore, the understanding and prediction of entrainment and transport dynamics of woody material of different shapes, density and dimensions is of great interest for...
conference paper 2011
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Uijttewaal, W.S.J. (author)
Shallow shear flows play an important role in the transverse transport of mass and momentum in rivers. In order to understand structure of the flow and the mechanism resulting in the particular turbulence properties, three types of shallow mixing layers are investigated each with a different cause for the velocity difference: inflow conditions,...
conference paper 2011
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Ottevanger, W. (author), Blanckaert, K.J.F. (author), Uijttewaal, W.S.J. (author)
Meandering rivers and streams are a common planform in the world’s populated areas. Furthermore the recent increased focus on renaturalization projects has lead policy makers to also consider the partial remeandering of previously trained rivers. Economic factors such as navigation, man-made infrastructure and valuable farm land set the boundary...
conference paper 2011
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Crosato, A. (author), Desta, F.B. (author), Cornelisse, J. (author), Uijttewaal, W.S.J. (author)
Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether they eventually reach an equilibrium shape, since short-term experiments...
conference paper 2011
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Ali, S. (author), Uijttewaal, W.S.J. (author)
conference paper 2011
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Ali, S. (author), Uijttewaal, W.S.J. (author)
At high water stages obstacles in the floodplains of a river contribute to the flow resistance. In particular the elevated vegetated parts are expected to play an important role. The objective of this study is to estimate and parameterize the form drag due to vegetated oblique weir-like obstacles. An experimental study has been carried out in...
conference paper 2011
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Crosato, A. (author), Mosselman, E. (author), Desta, F.B. (author), Uijttewaal, W.S.J. (author)
journal article 2011
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Crosato, A. (author), Desta, F.B. (author), Cornelisse, J. (author), Schuurman, F. (author), Uijttewaal, W.S.J. (author)
Migrating alternate bars form in alluvial channels as a result of morphodynamic instability. Extensive literature can be found on their origin and short-term development, but their long-term evolution has been poorly studied so far. In particular, it is not clear whether migrating bars eventually reach a (dynamic) equilibrium, as in previous...
journal article 2012
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